Safety device for sight-glasses.



. PATENTED SEPT; 8, 1908.-

I. 0., E. & M'. NORTHUP.

SAFETY DEVIGEFOR SIGHT GLASSES. APPLICATION FILED MAR. 29, 1907.

mam 14% s cm, WASHINGTON,-D:'C.

IORN O. NORTHUP AND EDWARD NORTHUP, OF KINGSTON, ARKANSAS, AND MALENNORTHUP UNITED STATES PAT NT oFnroE.

or LEAVENWORTH, WASHINGTON.

SAFETY DEVICE FOR SIGHT-GLASSES.

Specification of Letters Patent.

Patented Sept. 8, 1908.

Application filed March 29, 1907. Serial N 0. 365,392.

county of Madison and State of Arkansas,

and MALEN NORTHUP, a citizen of the United States, residing atLeavenworth, in the county of Chelan and State of Washington, haveinvented certain new and useful Improvements in Safety Devices forSight- Glasses, of which the following is a specification.

This invention relates to safety devices for sight glasses and relatesmore particularly to a combined plug cut-out and check valve for use inconnection with sight glasses for boilers and the like.

The invention has for one of its objects to improve and simplify theconstruction and operation of devices of this character so as to becomparatively simple and inexpensive to manufacture, thoroughly reliableand efficient in use, and easy and convenient to manipulate.

A further object of the invention is the provision of a cut-plug inwhich is arranged a flap or check valve that is normally held in suchposition that a forcible passage of steam through the out-out plug, aswhen the sight glass is broken, would automatically close the checkvalve and prevent the fall of steam pressure and the possible danger tothe engineer by the escaping steam.

Another object of the invention is the employment of a check valve sodesigned as to be readily opened, after once having been closed, by thesimple manipulation of the cutout valve.

With these objects and others in view, as will appear as the nature ofthe invention is betterunderstood, the invention comprises the variousnovel features of construction and arrangement of parts, which will bemore fully described hereinafter, and set forth with particularity inthe claims appended hereto.

In the accompanying drawing, which illustrates one of the embodiments ofthe invention:-Figure 1 is a front elevation of a sight glass and steampipe connected therewith, in which the combined cut-out and check valveis arranged. Fig. 2 is a vertical longitudinal sectional view of thevalve device showing the check valve in normal position by full lines,and in emergency position by dotted lines. Fig. 3 is a similar viewshowing the cut-out plug of the valve device in a different position.Fig. 4 is a horizontal sectional view showing the parts in elevation.

Similar reference characters are employed to designate similar partsthroughout the several figures of the drawings.

Referring to the drawings, 1 designates a steam boiler or otherapparatus containing liquid and vapor under pressure, and connectedtherewlth is a sight glass 2 which may be of any approved construction.In the present instance, the steam connection between the boiler andsight glass is alone shown. In the steam connection 3 is arranged thecombined cut-out and check valve, designated generally by 4, thatconstitutes the safety device for sight glass. This valve device 4 comrises a casing 5 constructed somewhat in t e shape of a cup and providedwith apertured and tapped bosses 6 for connection with the parts of thesteam pipe 3. Fitted in the casing 5 is a frusto-conical cutout lug 7that is provided with a diametrical y-extending passage 8, one end ofthe passage being enlarged to form a chamber 9. In the chamber 9 ispivoted a check valve 10 of the flap type, provided with a sphericallyconvex rubber or other portion for engaging the valve seat to close thepassage 8. The valve 10 is fulcrumed at 11 on lugs 12, and the saidvalve is provided with a stop or proj ection 13 adjacent the fulcrumportion thereof so as to engage one wall of the chamber 9 to hold thevalve in a normally inclined position. As shown in Fig. 2, the stop 13engages the wall 14 of the chamber 9 and holds the valve 10 so that itsfree end is disposed approximately in line with the center of thatportion of the pipe 3 that connects it with the steam space of theboiler. The object of this is to cause the sudden rush of steam throughthe pipe 3 and combined cut-out and check-valve, as for instance, whenthe sight glass is broken to pick up the check valve 10 and throw it tothe dotted line position shown in Fig. 2, thereby positively cutting offthe flow of steam. By turning the cut out plug through ninety degreesfrom its normal position, the solid portion of the plug 7 closes the aertured bosses 6 so that danger of steam lea ring is prevented.

Although only the steam pipe 3 is shown equipped with the valve device,it is to be understood that the water pipe 15, Fig. 1, that connectswith the water space of the boiler, may with advantage be provided witha combined cut-out and check valve. The cut-out plug is provided with athreaded stem 16 that extends through the side wall of the chamber 5 toreceive a nut 17 which holds the plug 7 firmly seated in the casing. Atthe side of the out-out plug 7, op osite from the stem 16, is a lever18, where y the plug can be turned by hand when desired.

From the foregoing description taken in connection with the accompanyingdrawing, the advantages of the construction and of the method ofoperation will be readily appreciated by those skilled in the art towhich the invention appertains. The normal position of the parts isshown in Fig. 2, and as long as the sight glass is in perfect condition,the check valve 10 will remain inactive. If, however, the sight glass isbroken, the check valve is' immediately closed.

In order to restore the check valve after a new sight glass is put in,the cut-out plug is turned half a revolution so that the pressure of thesteam will open the check valve and throw it to the position shown inFig. 3. Aftera pressure is thus restored in the sight glass, the cut-outplug is turned to its normal position, whereupon the check valve willautomatically open and rest in the position shown in Fig. 2.

Having thus described the invention, what is claimed, is p A device ofthe character described comprising a frusto-conical cup-shaped casingwith a turnable frusto-oonical shaped plug therein provided with adiametrically eX- tending passage which is enlarged at one end to form achamber, steam pipes on opposite ends of the casing arranged inalinement with the passage, a check valve pivoted in the chamber forclosing said passage and the steam pipe adjacent thereto, said checkvalve having a stop at right angles therewith, the terminal of whichcontacts with one wall of the chamber to hold the valve in an inclinedand partially open position, substantially as specified.

In testimony whereof We aflix our signatures in presence of twowitnesses.

IORN O. NORTHUP. EDWARD NORTI-IUP. Witnesses:

M. C. COGER, J. J. HORDY.

In testimony whereof I aflix my signature

